Examine source code of AutoRefresh

{
  "manifest_version": 2,
  "name": "AutoRefresh",
  "version": "0.7",
  "applications": {
    "gecko": {
      "id": "desenvolvimento@edu.criciuma.sc.gov.br_2"
    }
  },
  "permissions": [
    "http://*/*",
    "https://*/*"
  ],
  "browser_action": {
    "default_icon": "button/refresh.png",
    "default_title": "AutoRefresh",
    "default_popup": "popup/principal.html"
  },
  "content_scripts": [
    {
      "js": [
        "content_scripts/refresh.js"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ]
}